It is likely that a large number of genes contribute to nicotine dependence, as well as many environmental factors. This complexity represents a considerable challenge, but it also underscores the potential benefits of genetic studies of nicotine dependence. By understanding genetic factors that contribute to nicotine dependence, we may start to tease apart the different contributions of genes and environments that lead to heavy smoking, which in turn may improve interventions to reduce nicotine dependence and improve smoking cessation treatment.
